#pragma once
#include <iostream>
#include <string>
#include <strings.h>
#include <cerrno>
#include <cstring>
#include <cstdlib>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/un.h>
#include <functional>
#include <signal.h>

namespace Server
{
  using namespace std;

  static const string defaultIp = "0.0.0.0"; // TODO
  static const int gnum = 1024;
  enum
  {
    USAGE_ERR = 1,
    SOCKET_ERR,
    BIND_ERR,
    OPEN_ERR
  };

  typedef function<void(int, string, uint16_t, string)> func_t;
  class udpServer
  {

  public:
    udpServer(const func_t &callback, uint16_t &port, const string &ip = defaultIp)
        : _port(port), _ip(ip), _sockfd(-1), _callback(callback)
    {
    }
    void initServer()
    {
      // 创建socket
      _sockfd = socket(AF_INET, SOCK_DGRAM, 0);
      if (_sockfd == -1)
      {
        cerr << "socket error:" << errno << " : " << strerror(errno) << endl;
        exit(SOCKET_ERR);
      }
      cout << "\tsocket success:" << " : " << _sockfd << endl;
      // 绑定port,ip0
      // 服务器必须是一个明确的bind
      struct sockaddr_in local; // 定义了一个变量，栈，用户
      bzero(&local, sizeof(local));
      local.sin_family = AF_INET;
      local.sin_port = htons(_port); // 如果要给别人发消息，你的port和ip要发给别人
      // local.sin_addr.s_addr=inet_addr(_ip.c_str());//1.string->unint32_t 2.htons()
      local.sin_addr.s_addr = htonl(INADDR_ANY); // 任意地址bind，服务器的真实写法
      int n = bind(_sockfd, (struct sockaddr *)&local, sizeof(local));
      if (n == -1)
      {
        cerr << "bind error:" << errno << " : " << strerror(errno) << endl;
        exit(BIND_ERR);
      }
      // UDP Server的预备工作完成
    }
    void start()
    {

      // 服务器本质是一个死循环
      char buffer[gnum];

      for (;;)
      {
        
        struct sockaddr_in peer;
        socklen_t len = sizeof(peer);
        ssize_t s = recvfrom(_sockfd, buffer, sizeof(buffer) - 1, 0, (struct sockaddr *)&peer, &len);
        // 数据是什么，谁发的
        if (s > 0)
        {
          buffer[s] = 0;
          string clientip = inet_ntoa(peer.sin_addr); // 1.网络序列，2.int->点分十进制IP
          uint16_t clientport = ntohs(peer.sin_port);
          string message = buffer;
          cout << clientip << "[" << clientport << "]" << message << endl;
          // 对数据进行处理
          _callback(_sockfd, clientip, clientport, message);
        }
      }
    }
    ~udpServer()
    {
    }

  private:
    uint16_t _port;
    string _ip; // 实际上，一款网络服务器，不建议指明ip
    int _sockfd;
    func_t _callback;
  };
}
